Chrome Frame, Not Just for Internet Explorer

By looking at the code, it's obvious that the plugin is not limited to Internet Explorer. There's also a NPAPI plugin, which should work in browsers that support NPAPI: Firefox, Safari, Opera and other browsers. Here's a comment from one of the Chrome Frame files:

'ChromeFrameNPAPI: Implementation of the NPAPI plugin, which is responsible for hosting a chrome frame, i.e. an iframe like widget which hosts the the chrome window. This object delegates to Chrome.exe (via the Chrome IPC-based automation mechanism) for the actual rendering'.

A post from the Chromium blog explained the purpose of Google's plugin: "With Google Chrome Frame, developers can now take advantage of the latest open web technologies, even in Internet Explorer. From a faster Javascript engine, to support for current web technologies like HTML5's offline capabilities and <canvas>, to modern CSS/Layout handling, Google Chrome Frame enables these features within IE with no additional coding or testing for different browser versions."

Instead of asking users to download a different browser, Google and other companies that develop complex web applications can ask users to install Google Chrome Frame. This way, Google Chrome runs invisibly inside another browser.